Currently available approaches for selectively isolating large DNA fragments involve denaturing a target DNA, hybridizing complementary probes conjugated to biotin followed by isolation of the DNA-probe hybrids using streptavidin-coated beads. Another approach involves cleaving a target DNA with a restriction endonuclease, attaching biotinylated single-stranded DNA probes to the overhangs produced by the restriction endonuclease, and isolating the DNA-probe hybrids using streptavidin-coated beads. However, both of these methods suffer from many shortcomings including expense, inability to isolate large DNA fragments, and non-specific capture of unwanted DNA fragments.
Thus, there exists in the art a need to selectively isolate large DNA fragments without requiring denaturation steps to aid in targeted genomic re-sequencing projects, to improve diagnosis of genetic defects involving chromosomal aberrations, and to add to the available tools of molecular biology.